Operating and examining table



Feb. 25, 1947. H. g. SHAMPAWE 2,416,41

OPER ATIHG AND EXAMINING TABLE Filed Feb. 22, 1943 9 Sheets-Sheet l INVENTOR. HYMAN ROBERT SHAMPAINE Feb. 25, 1947.

H. RQSHAMPAINE OPERATING AND EXAMINING TABLE Filed Feb. 22, l943 9 Sheets-Sheet 2 1947'. H. R. SHAMPAINE I OPERATING AND EXAMINING TABLE Filed Feb. 22, 1943 9 Sheets-Sheet 3 IN VEN TOR.

HYMAN ROBERTSHAMPAINE Feb. 25, 1947.

H. R. SHAMPAINE OPERATING AND EXAMINING TABLE Filed Feb. 22, 1943 9 Sheets-Sheet 4 INVENTOR. HYMAN ROBERT-SHAMPAINE Feb. 25, 1947. M M 2,416,410 I OPERATING AND EXAMINING TABLE Filed Feb. 22,194: I 9 Sheets-Sheet 5 if 4 75 9a 79% z INVENTOR. HYMAN ROBERT SHAMPAI NE 47- TORNAEY Feb. 25, 1947. sHAMPAlNE- 2,416,410

' OPERATING AND EXAMINING TABLE Filed Feb. '22, 1945 9 Sheets-Sheet 6 1 INVENTOR. HYMAN ROBERT SHAMPAINE ,4 7- Ta/eA/Ey Feb. 25, 1947. MF 2,416,410

OPERATING AND EXAMINING TABLE Filed Feb. 22, 1945 9 Sheets-Sheet FIG.I6.

' INVENTOR. HYMAN ROBERT SHAMPAINE Feb. 25, 1947. H. R. SHAMPAINE OPERATING AND EXAMINING TABLE Filed Feb. 22, 1943 9 Sheets-Sheet 8 A-rmRA/Ey 7- H. RQSHAMPAINE OPERATING AND EXAMINING TABLE Filed Feb. 22, 1943 9 Sheets-Sheet 9 INVENTORY HYMAN ROBERT SHAMPAINE '14 TrOIPA/E r e the table;

Patented Feb. 25, 1947 UNITED STATES,PATENT. "OFFICE This invention relates generally to surgical apparatus and, more particularly, to a certain new and useful improvement in surgical apparatus of the type commonly known asoperating or examining tables.

The invention has for its principal object the provision of an operating table having an articulated top which, as a, unit, may be laterally and longitudinally tilted by the action of a single shaft.

Morespecifically, the present invention has for an object the provision of a table of the character mentioned uniquely constructed for simplifying and reducing the number of controls heretofore requiring separate and independent of the anesthetist, technician, or other operator .in adjusting the top-sections to meet the requirements of the particular operation or examination.

The invention has for another object the provision in a table of the type described of an arrangement whereby all of the controls for the respective top-sections are withineasy and convenient reach of an operator seated at the head- Iend of the table, and such that alladjustments may be made by so-called touch control, without Iylsual observation of dials or complicated levers which might distractthe attention durin'g'criti'cal "moments of an operation or examination, Another object of the invention is the provision in the table of improved, compact operating mechanism, which is especially well adapted for enclosure in a housing of relatively small dimen- 'various positions of adjustment;

7 Figure 2 is a top plan view principally of the center or lower body section of the table, with the upper surface panel thereof removed to reveal theoperating mechanism;

Figure 3 is an enlarged sectional view taken approximately on the line 3-3, Figure 2, showing some of the mechanism for effecting angular adjustments of the back-restand leg-sections of Figure 4 is an enlarged sectional view taken r15 manipulation, to the end of facilitating the work 7 to Leah Ree'Shani'paine, (lla'yton, Mo I Application February 22, 1943, Serial N0." i7.6,'69.9

rolaims; (01. 311 -71) .t Figure 5. is an enlarged sectional view taken approximately on the line 55. Figure 2, showe ing adjustment linkage for the back-rest section;

Figure 6 is arr-enlarged sectional view taken approximately on the line 6--6, Figure 2, showing generally the mechanism for obtaining height adjustment and the gearing for effecting angular adjustment of the center-section and lateraltilt of the entire'table-top;

Figure '7 is an enlarged detail sectional plan view taken approximately on the line 1-1, Figure Figure 8 is an enlarged sectional elevation taken approximately on the line 88, Figure 2, showing the adjusting and control means for the top center-section and lateral tilt of the table Figure 9 is an enlarged sectional view of the table taken approximately on the line 9--9, Figure 2, chiefly illustrating the means for obtaining height adjustment and lateral tilt of the table top'; l H a Figure 10 is an enlarged sectional view of the table taken approximately on the line Ill-40,

Figure 2, showing portions of the gearing foreffecting angular adjustment of the center and back-rest sections; 7 a y 1 Figure 11.is an enlarged sectional view of the tablev taken approximately on the line ll-H, Figure 2, further illustrating. gearing for adjusting the leg-rest;

Figure 12 is an enlarged fragmentary side view of some of the gear shift mechanism for obtaining selective adjustments of top sections by a single control agency; 1 Figure 13 is a vertical section of the gearshift control taken approximately on the line 13-43, Figure12; 1

Figure 14 is a transverse section of'the gear controlshaft takenlapproximately onthe line I l-I4, Figure 12, showing the shaft housing and bearings;

Figure 15 is a sectional plan view of the gear shift. control taken approximately on the line l5l5,Figure 13; t V v v Figure 16 is an enlarged transverse section taken approximately onthe line Iii-I6, Figure 2,

showing certain construction features of the top center-section; g r v Figure 1'7 is a bottom plan view of the base structure of the table;

Figure 18 (sheet 4) is a detail section taken on the line l8-|8, Figure 17, showing the pedal for releasing the table-top for rotary actuation; Figure 19 is a detail sectiontak/en on the line 1 and leg-rest section 5. sections, but not specifically here shown, there is preferably provided a foot-rest formed as a 1 hinged extension of the leg-rest 5, and a body elevator or kidney bridge which forms a part of the lower body section 4 adjacent the backrest-3. 7

disposed in relatively elevated positions. 1 it is desired to bodily move the table, the pedal 16 is depressed, thereby causing rounded cam- ;ming noses I8, best seen in Figure 19, of rockerarms 1 5 to force the roller equipped endsof levers 9 upwardly to a position against the under surface of .the base 6 and the outer end-portions of the levers fi downwardly for engaging the casters 1 B with the floor or other support and accordingly Ill-l9, Figure 17, showing the means for adjusting and controlling the base casters;

Figure 20 is a detail section taken on the line 20-48, Figure 17, showing the caster control jpedal; "and Figure 21 is a transverse sectiontaken on the Referring now more in detail and by reference 1 line 2 i2 I, Figure 17, showing the locking means for the caster control pedal.

latter, in the present instance, consists of four individually adjustable sections, namely, a headrest 2, back-rest 3, lower body-or seat section 4, In addition to such top I'he pedestal l includes a hollow, generally rectangular base-member 6 having leg formations 1 at the four corners thereof, and, as appears in Figures 17 and 19, concealed within each leg formation I, is a caster assembly 8 mounted on the outer end of a lever 9 individual thereto.

The several levers 9 terminate, as shown, in-

I wardly approximately at the transverse center line of the table and are fulcrumed intermediate their length on respective fixed bearing-studs HI that project inwardly from the skirt-portion ll, of the base-member B, the levers 9 being each provided at its inner end with a pin I2 support ingfor rotation a roller 12.

Extending transversely within the base 6 below the levers 9, is a shaft l3 centrally off-set toward A pair of somewhat angular rockersecured at an end to shaft l3 extends rearwardly of the table through a suitable opening I! in the base-skirt H, where it is -conveniently accessible 1 to an operator seated at the control -or so-called head-end of the table. l

-Under normal conditions of use, the .base 6 rests solidly and firmly on .a floor .or other support, the casters 8 and likewise the pedal lfilbeing When elevating or raising the base '8 :from the floor,

so that the table may 'besbodily conveniently I rolled on the casters 8.

Means for locking the casters a in their table serving as a counterweight for maintaining the Ylatch or detent H9 in position automaticallyto lockthe depressed pedal 16 and further serving to'limit movement of-the detent t9 by i s ab t- 1 ment with stop-projections 2|. It will be understood, of course, that, on quick depression of the pedal it, its projection 20 will be released from engagement with the detent I9.

As best seen in Figure 6, the base-member 6 has an approximately central annular opening, as at 6 and at said opening is provided with a short upstanding peripheral flange 22 and a series of spaced, depending lugs '23; 24 designates a ring having lateral lugs 25 appropriately spaced to mate with the lugs 23, to which they are secured as by bolts 26, and a rabbet, as at 24*,

formed in the inner circumferential face of the ring 24, together with a separable overlying ring 2'1, "provide an annular seat and journal for a bearing shoulder 28 on the lower end of a pedestal or column member 29, which constitutes the piston of hydraulically operable means for adjustingthe height of the table-top and snugly fits the bore of a coatin cylinder member 30, which is closed at its upper end as by an end-plated]:

It may be here remarked that a suitable pump .(not shown) concealed within the pedestal 29 is arranged for actuation :as .bya pedal 32, which extends to the operating end of the base 6 at one side of the caster control pedal I 6 and serves, inthe well known manner, to force suitable fluid into the cylinder-space and thereby elevate the cylinder and table-top mounted thereon, the outefiow of fluid from the cylinder to lower the tabletop being controlled by a suitable valve (not shown) also operated by pedal 32, as will be well understood. a

The pedestal or column 29 and the table-top which itsupports, being journalled in the base B'by the companion ring-member 24 and annular shoulder 28, is rotatable about the vertical axis of the piston-cylinder assembly. Normally, rotation of the table-top is prevented by a locking mechanism also shown in Figure 6 and which comprises a suitable brake-shoe 33 mounted on the inner end of a plunger-rod 34 and urged or biased into frictional engagement with the bearing-shoulder 28 by a spring 35. Outward displacement or retraction of the brake-shoe 33 to release the column 29 for rotation is effected by means of a pedal 36 fixed to a shaft 31, on which a rocker arm 38 is secured; and arranged for engagement with a lateral projection 39 o'r'1 plunger rod 34. It should be understood that, to render the locking device entirely effective, relative rotation of the piston and cylinder members of the pedestal is preventedby suitable co} operative means thereon, as, While not here shown, key and key-way provisions, for example;

audit will be observed by reference to Figure 17 that the control pedal 38 has its tread portion disposed adjacent the treads of pedals l6 and 32 at the rear or head-end of the table,.where all such pedals are within easy, convenient reach of the operator or technician.

Turning now to the table-top surmounting the pedestal-cylinder 3.0 and suitably bolted to the end-plate 3|,asalso shown'in Figures 6 and 9.,

is a trunnion-member 40, to which is secured the upper end of a depending annular apron" that provides a housing for the column 29 The trunnion-member 40 has a pair of upstanding bearing arms 42 :and 43, in which are received the ends of a horizontal axle-shaft 44 for sup-,- porting the table-top and pivotally enabling lat eral tilting thereof; 3 I :Bearing arm 42 is provided with-an inwardly ofi-set extension 45, t'o'which is bolted a sector;

5. shaped worm gear 45, disposed in a vertical plane axially ofthe pedestal column 29. r A A'stanchio n or coupler member 41 isjournalled at its lower end on the axle-shaft 44, so

' as-to permit oflateral tilting thereof, and formed on one side of the member 41 and located above the gear sector 45, is a pair of bearing-bosses 48, in which is journalled a transverse shaft 49, keyed on which and meshing with gear-sector 4B, is a table-top lateral tilting worm 50 preferably provided at its ends with thrust bearings 5|, as best seen in Figures 2 and 9, and adapted to be rotated by means of a bevel gear 52 in conjunction with other gearing presently described, gear, 52 being fixed on a projecting end-portion of a shaft 48 at a point near one side of the tabletop. As further seen in Figure 9, a sleeve 58 encloses the intermediate portion of shaft 49 and hasinstalled therein suitable anti-friction shaft bearings 54. j

As best appears in Figure 6, there is formed on the stanchion member 41, on the side thereof opposite the worm 50, a, longitudinally projecting flange 55, to which is fixed a worm gear sector 55, meshing with which is a worm 51 carried by the center section 4 of the tab-le-top, such worm and gear assembly, with other agencies presently described, enabling angular adjustment of the table-top in a longitudinal plane.

As best seen in Figures 2, 6, 8, 9, and 10, the center section 4 of the table-top has a frame structure 58, the members ofwhich are preferably angulate in cross-section, and formed integrally with the side members of the frame 58, are depending rigid side panels 59 and 50 that serve to support and shield the control mechanism. The posterior end-portion of frame 58 is formed to provide a semi-circular recess, as at 58, which, together with a complementary recess, as'a t '5, in the adjacent end of the leg-rest section 5, provide an unobstructed access opening 60, especially useful in perineal surgery; At the opposite or anterior end of frame-portion 58, is

a preferably integrally formed depending plate tion 58 and end-plate 6|, as best seen in Figures 6 and 9, and fixed to the lower end of shaft 64, is a bevel gear 68, which meshes with a companion gear 59 secured to the end of a transverse shaft 10 supported by bearing'arms H formed on the end-plate 8i and extending toward the right-hand side of the table for mounting a beveled driving gear 12. I The table, as will be seen, includes a unified control for its top adjustments,- namely, those for effecting lateral and longitudinal tilt, and such control, in part, comprises a shaft" that ex: tends "below and along the right-hand side of the table-to from approximately the center to its head-end and, as best appears in Figures 2 and 8, is journalled for rotatory and endwise movement by: a pair of suitably spaced bearing-arms T4, 15, the former being located near the rearv end of the shaft and projecting from the side panel 59 and the latter being disposed at the front;

end of a shaft-housing rigidly secured at its opposite end to the end-plate 6! of the'table-top" center-section, as seen in Figure 8.

- Shaft 13 is'adapted for endwise, as well as ro-l tary, movement, as has been mentioned, ana'fixed to and upon its rear end, is a bevel gear- 16 for meshing engagement with bevel gear 52 when shaft 13 is axially displaced or shifted rearwardly or inwardly.

j A second'bevel gear 11 is appropriately positioned on, and fixed to, shaft 13, as also seen in the gears 52 and 16 at the same time becoming mutually disengagedJ Rotation of shaft I3 is preferably manually ef fected bymeans of a hand-wheel 18 located on its forward extremity, and axial shifting move 7 ment of shaft" is accomplished by means'o'f a lever 19 in either of .its operating positions.

lever 18 located immediately behind wheel 18,:as seen in Figures 8 and 12, so that lever l9may be manipulated without necessitating removal of the hand of the technician from the wheel 18. I

As clearly appears in Figures 12 and 15, the hub-portion of levers 19 is journalled on shaft 13, so that rotary actuationi thereof will notbe imparted to the lever 19, yet the hub-portion 80 is confined between the hand-wheel 18 and a fixed collar 8|, so that inward or outward lateral displacement of the lever 19 will be transmitted to the shaft 13. Such displacement or shifting of the lever 19 is conveniently accomplished as a concomitant to its swinging movement by means of a guide or sector-flange 82 formed on or other wise suitably secured to the end of the shaft hous ing I5 and having an arcuate periphery disposed in a plane oblique to the axis of shaft 13, lever 19 being provided with an offset extension 83 grooved at its inner end to receive and closely fit about the peripheral margin of fiange 82. Consequently, lever 19, when swung from one to the other of its extreme positions, is caused to.

travel in a fore and aft direction, thereby selectively' meshing gear 16 with gear 52 or gear 11, with gear 12 and enabling the operator or technician to readily control through the hand-wheel l8 desired longitudinal and lateral tilt of the table-top. 7

As further seen in Figure 15, the lever exten sion 83 is bored longitudinally to accommodate a plunger 84, threaded to ahandle-element or knob 85 and adapted at its inner or head-end 86 to seat in either of two'rounded or arcuate depressions 81in the flange 82 for retaining the spring 88 coiled about the plunger 84 and abutting the head 86 and the base of extension 83 applies sufiicient inward biasing force to the plunger 84 for preventing casual or unintended displacement of the lever 19, the pressure of spring 88, however, being such as to permit the plunger 84 automatically to move outwardly un-1 i stood. Accordingly, theoperator is not required to remove his hand'from the hand-wheel 18 in order to'shift lever l9, but may engage and shift,

the lever 19 with anextended finger while turning the hand-wheel i8, thus makingfor so-called touch control and greatly facilitating the work of the operator or technician.

';Turning now to the construction of, and pro-, vision for adjusting, the back-rest section 3 and leg-rest section 5, best seen in, Figures 2," 3, 4,

and 16, such sections substantially correspond'in' deadening material;

spective bottom layers M are preferably formed 1 and the opposite end 1 arm 62. a

7 structure; to the center tions' 3 and 5 also are generally rectangular in plan and. have frame structures .89 and 90, respectively, having suitably connected angular side and end members, and it may be here mentioned that the several top sections of the table are" preferably constructed of two layers of sheet metal interposed by a layer of a suitable sound- Of such sections, the reof steel plates of appropriate thickness to pro videfor rigidity, and the upperlayers 92 are desirably formed of thin sheets of stainless steel or the like and are turned downwardly over the sides. and lower margins of the frames, where they-- are secured for constituting facings for such surfaces. As appears in Figure 16, the side panels 59 of the center section a are recessed for accommodating removable facingmembers 94, which aid, as shown, in securing the turned-under margins of the upper layer 92 of such section.

and 5 are hingedly connected to the respective opposite margins of the center section 4 by means of pairs of pintle-joined projecting hinge-knuckles 95 and 85, which latter are preferably integrally formed on the framerportions 89, 90. It may be mentioned that, as also seen in Figure 2, in the case of the foot-rest section 5, short pintles 91 are preferably employed for connecting thehinge knuckles 95, so as not to obstruct the perineal opening Gil while a single, elongated pintle 98, preferably provided with a, covering sleeve as, joins together the hinge knuckles 96.

The back-rest section 3 is supported and its angular position adjusted relative to the center section t in a mannernow to be described; Projecting inwardly from theside panel 66, as best seen in Figures 3 and 9, is apair of suitably spaced bearing-lugs Hi0 rotarily supporting a shaft IllI projecting downwardly beyond the lower bearinglug I08- Fixed on the lower end of shaft I Ill, is

l a downwardly facing bevelgear I02, and secured between suitable thrust bearings on shaft IIJI, is 1 a worm ill-t, which meshes with a worm sector gear I04 secured on a transverse shaft I05, onesection 4,.in'that the sec- As best seen in Figure 2, the top-sections? fixed upon its lower end, A transverseshaftjrll V journalled in the sidec panel 69 and the-rib; II-5. isdriven from the worm I I2 by means of a worm sector gear H8, and said shaft III .isoperatively' connected to the leg-rest 5 by means of a crank-.1

'arm H9, a link I20, pivot pins. I2I and I22, and

bearingcleat I23, a shield orihousingIZlI for such worm' and gear mechanism preferablydepending from the rear margin of the center section 4,. as'

shown. g Selective control and adjustment of thebackrestsection 3 and leg section5are obtained by meanswhichas further seen in Figures am 3,, include a shaft I that extends along the. table and, a hand-wheel I 26 on the forward or,

head-end thereof, where it is conveniently ac-i cessible to the left hand of the operator or tech-- nician. Sh'aft I25 is journalled adjacent its rear end in a bearing-lug I21 and adjacent its, forward end in a bearing H28 mounted in the for ward end of a shaft housing I29 bolted or otherwise secured to the depending center section.

frame-plate SI. As in the case of. control shaft end of which is journalled in the side panel 60 in the adjacent bearing A crank-arm or link H35 having its inner end 5 fixed to shaft I65 projects forwardly through an 1 opening I91 in end-plate SI and is connected at j itsforward end to a link Hi8 by means of a pivot pin I09, the; link IDB' atits upper end being pivotally' connected. by a pin H6 to. a-bearing c leat III secured to the underside of top-section 3. q worm H13 byits gear Ifilwillcause shaft, I05

to rotate and actuate crank-arm I86, the top section Braising or lowering with the forward It may be observed 1 that the. link IE8 andjbowed shape ofcrank-arm I66 permit the latter to clear the hinge 'pin 98,.

1 so that the upper body, or back-rest section 3' may be fully raised to a vertical or chair positions It will now be evident that rotation of end of the crank-arm IBIS.

Support and adjustment'of the leg section 5 are obtained in much the same manner as described in connection with the section 3. Thus,.

as best seen in Figures 2 and 3, a worm gear IIZ' j is keyed to a vertical shaft H3 journalled in suitably spaced bearing-plates H4 extending transversely between the sidepanel' 6!! and a longitudin alrib'II5 of the frame, of leg-rest 5. Shaft.

= II3 projects downwardly beyond the lower plate JII4andhas an'upwardl'y facing bevel gear I.I6..'

of my invention.

73 located at the right-hand side of the table, shaft I25 is adapted for both endwise shifting and rotary movement and has secured thereon; a bevel gear I36 arranged to mesh with gear I02- when the shaft I25 is shifted forwardly and a bevel gear I3I arranged to mesh with gear IIG when the shaft 25 is shifted rearwardly.

Also, while not specifically shown, means which are preferably of the .same character as those employed for shifting control-shaft I3 are pref erably provided for shifting the control-shaft I25, so that unified yet selective touch control of the leg section 5 and back-rest section 3 may be had at the hand-wheel I26.

The head-rest section 2 at the forward end of the back-rest 3 is preferably mounted so as to be both removable and adjustable, and it will be understood that, while not here shown, suitable means may be provided for retaining the head rest 2 in any of its adjusted positions.

As will be observed, the operating tableof my invention. is extremely simple of adjustment and control. and efiici'ently accomplishes and achieves in all respects the objects stated, the relative;

embodiment thereof, changes in the form, con? struction, arrangement, and combination of the, several parts of the table may be made and sub stituted for those herein shown and described wti-hout departing from the nature and principle Having thus described my invention, what I claim and desire to secure by Letters Patent is:

1'. An operating table includingya pedestal, a

top-section, means comprising separate worm and gear assemblies for mounting the top-sew tion, on the pedestal for longitudinal and lateral tilting, and means comprising'a common'shaft for actuating either of said gear assemblies for selectively effecting longitudinal or lateral. tiltin of-thetop-section.

2. In an operating table, a pedestal, a topsection, means comprising separate worm and gear assemblies for mounting the top-section on the pedestal for longitudinal and lateral tilting, an actuating shaft mounted for shiftable and rotar-y movement on the table, and means for engaging the shaft with respective gear assemblies for eifecting selective longitudinal or lateral tilting of the top-section.

3. In an operating table, a pedestal, a top-section, means comprising separate worm and gear assemblies for mounting the top-section on the pedestal for longitudinal and lateral tilting, an actuating shaft mounted for shiftable and endwise movement on the table, gears on the shaft for respective engagement with said assemblies for effecting selective longitudinal or lateral tilting of the top-section, and control means including a manipulating member pivoted on the shaft for selectively connecting the shaft-gears with said assemblies.

4. In an operating table, a pedestal, a topsection, means comprising a plurality of gear assemblies for mounting the top-section on the pedestal for longitudinal and lateral tilting, and means for actuating the tilting means for selec tively effecting longitudinal or lateral tilting of the top-section, said last means comprising a drive shaft mounted for endwise and rotary movement on the top-section, gears on the shaft for respective engagement with said assemblies, a member for rotarily actuating the shaft, and a manipulating member located adjacent the operating member for endwise shifting the shaft.

5. In an adjustable operating table, a'pedestal, a top-section, means comprising gear assemblies connected to the top-section and pedestal and an endwise shiftable drive shaft having gears fixed thereon for engagement with respective gear assemblies responsively to shifting movement of the shaft for effecting longitudinal or lateral tilt of the top-section, and means comprising a fixed guide plate disposed obliquely to the shaft and a lever journalled on the shaft having a portion thereof constrained for movement along the margin of said guide plate for shifting said shaft.

6. In an operating table, a pedestal, a top- 10 section, means comprising a coupler pivotally mounted on the pedestal and gear assemblies intermediate the coupler and top-section for mounting the top-section on the pedestal for longitudinal and lateral tilting, and means including a single endwise shiftable and rotary shaft on the table for actuating the tilting means for selectively effecting longitudinal or lateral tilting of the top-section relatively to the pedestal.

7. An operating table including a pedestal, a top-section, means adjustably mounting the topsection on the pedestal for lateral and longitudinal tilting, said means including a coupling member, relatively transversely disposed coupling pins interconnecting said member to said pedestal and top-section, a Worm and gear combination for regulating tilting of said coupling member on the pedestal, a second Worm and gear combination for regulating tilting of the top-section on said coupling member, parallel drive shafts for said worms extending transversely of the top-section, a single endwise adjustable control shaft carried by and extending longitudinally of the top-section, and means operable in response to endwise adjustment of said control shaft for selectively connecting the same to either of said drive shafts.

HYMAN ROBERT SHAMPAINE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,571,205 Laurent Feb. 2, 1926 1,267,812 Smith May 28, 1918 1,746,035 Fitting, Jr Feb. 4, 1930 1,740,906 Rothanszky et a1. Dec. 24, 1929 2,092,266 Talas Sept. 7, 1937 1,814,482 Miller July 14,1931 2,172,941 Manning Sept. 12, 1939 2,217,783 Bell Oct. 15, 1940 FOREIGN PATENTS Number Country Date 434,100 French Nov. 15, 1911 

